This invention pertains to an instrument and method for automating the conventional suturing process routinely performed during open and endoscopic surgeries.
Conventional suturing, where a practitioner manually sutures tissues with a needle and suture material, is still the preferred method and has not been replaced by any other technique. However, it is a time consuming process and this inconvenience becomes even more pronounced during endoscopic surgeries.
Most of the time a simple interrupted suture is what is needed, and a surgeon's knot is the type of knot used. In order to tie a simple interrupted suture, a needle, a suture material attached to the needle and three additional instruments are generally used: a needle holder, a forceps and a pair of scissors.
To suture during an open surgical operation, first an assistant takes a needle out of a needle dispenser with a needle holder and then hands the needle holder to the practitioner with the tip of the needle pointing left or right depending on whether the practitioner is right- or left-handed. The practitioner manipulates and positions the tissues or the structures to be sutured with a forceps in his/her other hand and passes the needle and the attached suture material through them. To form a surgeon's knot, first a double-wrap throw is made, followed by a single-wrap throw in the reverse direction. To make a double-wrap throw, the needle-attached end of the suture material is wrapped around the distal body of the needle holder twice in the same direction. The other end of the suture material is grasped with the needle holder to pull through the wrappings made around the needle holder while the needle-attached end of the suture material is pulled in the opposite direction. After desired tension on the tissues or structures within this first loop is attained, the ends of the suture material are released. To make a single-wrap throw, the same process is repeated wrapping around the needle holder only once and in the reverse direction. This creates a second loop, and its size is reduced to a minimum by pulling on the ends of the suture material to secure the knot. Following final tightening the excess lengths of the suture material on both ends are cut, usually by the assisting person.
Endoscopic surgeries, on the other hand, are surgeries performed with the aid of an endoscope, which is basically a video camera. The surgical site is reached through one or more small ports. Special elongated instruments including an endoscope are introduced through these ports. Direct view of the surgical site is not available, but a limited indirect view is provided by the endoscope. Therefore, simple but time-consuming maneuvers described above for an open surgery (such as wrapping a suture material around an instrument, passing the needle from one instrument to another) become more tedious and more time consuming. Incidents such as dropping the needle may become a real issue. Therefore, most of the efforts to advance the state of the art of suturing have been intended to facilitate endoscopic suturing.
Among all the steps of suturing, tying a knot is the lengthiest and the one that involves the most manipulation, and several patents address this step. For example, U.S. Pat. Nos. 5,002,563 (Pyka, et al), 5,259,846 (Granger, et al), 5,368,599 (Hirsh, et al.), 5,403,346 (Loeser), 5,520,702 (Sauer, et al.), 4,592,355 (Antebi), 5,123,913 (Wilk, et al.), 5,330,503 (Yoon), 5,643,295 (Yoon), 4,981,149 (Yoon, et al.), 5,683,417 (Cooper), 5,931,855 (Buncke), 5,984,933 (Yoon), 5,919,208 (Valenti), 6,010,525 (Bonutti, et al.), 6,066,160 (Colvin, et al.), and 6,099,553 (Hart, et al.), are representative of suture devices, or suture materials of special structures designed to avoid forming knots. U.S. Pat. Nos. 5,725,522 (Sinofsky), 5,565,122 (Zinnbauer, et al.), 6,077,277 (Mollenauer, et al.), 5,417,700 (Egan), and 6,106,545 (Egan) suggest using laser radiation or radiant heat to effect fusion instead of tying knots. These patents are mostly for techniques to avoid tying a knot altogether. The ones on facilitating tying knots, on the other hand, are almost exclusively for endoscopic surgeries.
There are at least three ways of tying sutures during an endoscopic surgery. One way is taking both ends of the suture material out after passing it through the tissue and forming the knot extracorporeally and pushing it back inside the surgical field. U.S. Pat. Nos. 5,084,058 (Li), 5,087,263 (Li), 5,257,637 (El Gazayerli), 5,403,330 (Tuason), 5,769,863 (Garrison), 5,234,444 (Christondias), 5,217,471 (Burkhart), and U.S. Pat. No. 5,752,964 (Mericle) are examples of knot pushers. A second way of tying sutures during endoscopic procedures is of course forming and tying knots intracorporeally, which is extremely tedious. However, there are some instruments designed to help tying knots intracorporeally especially for forming loops. U.S. Pat. Nos. 5,192,287 (Fournier, et al.), 5,201,744 (Jones), 5,716,368 (de la Torre, et al.), 5,810,852 (Greenberg, et al.), 5,383,877 (Clarke), 6,045,561 (Marshall, et al.), 6,086,601 (Yoon), 5,234,443 (Phan, et al.), 4,641,652 (Hatterer, et al.), and 5,480,406 (Nolan, et al.) are examples of this class.
Use of preformed knotted loops is the third way of tying sutures during endoscopic surgeries. U.S. Pat. Nos. 5,405,352 (Weston), 5,330,491 (Walker, et al.), 5,449,367 (Kadry), 5,643,293 (Kogasaka, et al.), 5,846,254 (Schulze, et al.), 5,211,650 (Noda), 5,320,629 (Noda, et al.), and 5,144,961 (Chen, et al.) disclose devices using preformed knotted loops or partially tied knots within which the needle is passed and the suture is tied.
There are also patents addressing the steps of suturing other than tying knots, such as manipulation of the needle and suture threading. Some of these inventions also assist forming knots during endoscopic procedures. Others disclose a specific needle or a needle holder design. Some examples of this class of patents are U.S. Pat. Nos. 4,373,530 (Kilejian), 4,164,225 (Johnson, et al.), 4,345,601 (Fukuda), 4,557,265 (Andersson), 4,596,249 (Freda, et al.), 5,318,577 (Li), 5,474,565 (Trott), 5,569,270 (Weng), 5,540,705 (Meade, et al.), 5,520,703 (Essig, et al.), 5,772,672 (Toy, et al.), 5,746,754 (Chan), 5,741,279 (Gordon, et al.), 5,665,096 (Yoon), 4,957,498 (Caspari, et al.), 5,776,150 (Nolan, et al.), 5,766,186 (Faraz, et al.), 5,951,587 (Qureshi, et al.), 5,954,733 (Yoon), 5,152,769 (Baber), 6,074,404 (Stalker, et al.), 6,071,289 (Stefanchik, et al.), 5,814,054 (Kortenbach, et al.), 5,895,395 (Yeung), and 5,364,409 (Kuwabara, et al.)
A particularly successful invention in this field has been the surgical stapler. In some limited set of applications, the surgical stapler has been able to replace conventional suturing for many practitioners. There are quite a number of patents disclosing surgical staplers designed to be used during open surgeries (e.g., U.S. Pat. Nos. 4,470,532 (Froehlich), 5,893,855 (Jacobs), 4,664,305 (Blake, III, et al.), 4,583,670 (Alvarado), RE28,932 (Noiles, et al.), 4,592,498 (Braun, et al.), 3,949,924 (Green), 5,697,543 (Burdorff) or endoscopic surgeries (e.g., U.S. Pat. Nos. 5,392,978 (Velez, et al.), 5,470,010 (Rothfuss, et al.), 5,553,765 (Knodel, et al.), 5,554,169 (Green, et al.), 5,810,855 (Rayburn, et al.), 5,829,662 (Allen, et al.).
Surgical staplers are actually very similar to their office counterparts. They dispatch staples to clip and hold tissue together. The surgical staples, however, can be made of metal or absorbable materials. They are designed to combine the functions of a needle and a suture material in one body. They need to penetrate the tissue like a needle and hold the grasped tissue like a tied suture material. Metal staples may be thought of needles bent and left in tissue. Even though the ends of staples are left free, since they are able to preserve their new shape they fix the tissue edges. Metal staples are not absorbable. Absorbable staples, on the other hand, require an extremely large amount of material to be introduced into the body to provide a secure fastening (see U.S. Pat. No. 5,507,776 (Hempel)).
The reason that staplers have found applications in today's field of surgery is often not because they are superior to conventional suturing in terms of the results they provide, but because it is faster to staple with a simple maneuver. One of the disadvantages of staplers is that the tension applied on the grasped tissue by staples cannot be adjusted. It is sometimes too loose, sometimes too tight. Also scars caused by stapling are usually worse than scars with conventional suturing. This is why staplers are usually used where esthetical results are not sought. In addition many surgeons prefer the security of sutures to staples.
A suturing apparatus described by Klundt, et al. (U.S. Pat. No. 5,496,334) automatically sutures by performing a single-thread overcast stitching operation, like a sewing machine; however this apparatus cannot tie single interrupted sutures.
Therefore, there is a need for an instrument that automates what a practitioner does during a conventional suturing process, which in spite of many recent inventions is often still the preferred method of closing wounds. Such an instrument would preferably combine the practicality of a stapler with the advantages of conventional suturing.